Before I start, this is a good 1v1 game to practice on!: 1v1 Game!.
First things first, you need a good pc. This is because without a pc you can lag very badly and only play on like for example on 30 fps (Frames Per Second) and also your pc might not be able to open some games.
Here's a list of good things you can get for your pc.:
Second of all, practise. You have to practice for a long time before you become a professional gamer and don't forget to always practise on your weak points to make them strong and practise on your strong points to make them stronger!
Finally, learn new tactics from others. You may think that learning from others won't make you better, but the opposite is true.